#define _CRT_SECURE_NO_WARNINGS 1

#include <stdio.h>

int main() {
    int arr[4] = { 0 };
    int i, j;
    int max = 0;
    for (i = 0; i < 4; i++)
    {
        scanf("%d", &arr[i]);
    }
    for (j = 0; j < 4; j++)
    {
        if (max < arr[j])max = arr[j];
    }
    printf("%d", max);
    return 0;
}